reading data from spss file and using stat package - r

Question

I usually use spss but needed to use a special stats package in R for the same dataset. I have found ways to read my spss data into r but I need to analyze this data with a statistical package.
The code I have to read the data is:
>RED.data<-read.spss("RED.sav", use.value.labels=TRUE, to.data.frame=TRUE)
The code for the stats package:
>library(twang)
>data(DTA)
>set.seed(1)
>mnps.RED<-mnps(treat~illact+crimjust+subprob, data=RED, estimand="ATT", verbose=FALSE, stop.method=c("es.mean", "ks.mean"), n.trees=3000)
I know I am missing a step between these but can't figure this out so far. I am confused about the formats of the data and their usage. What is the difference between the codes below and how can I use them?
>RED=read.csv("RED.csv")
>attach(RED)
>data(RED)
Thanks for your help!

Answer 1

Why not use the SPSS Statistics R integration apis for this? You would read the data into Statistics and then run R code like this.
begin program r.
dta = spssdata.GetDataFromSPSS()
mnps.RED<-mnps(treat~illact+crimjust+subprob, data=data, estimand...)
print(mnps.RED) # or whateverd else you need from the output.
end program.
You need to install the appropriate version of R and the free R Essentials for your version of Statistics to make this work. More details can be provided if you indicate what version of Statistics and what platform you are using.

Answer 2

Thanks for the help, JKP and Laterow. I'm using R 3.2.3 and SPSS 23.
Also, I made a mistake in the code in the original question. Here is the code again:
This is what I found for reading SPSS data into R :
require(foreign)
RED.data<-read.spss("RED.sav", use.value.labels=TRUE, to.data.frame=TRUE)
but I am not sure it is necessary to do this if I want to analyze the data with the "twang" package code below:
library(twang)
data(RED)
set.seed(1)
mnps.RED<-mnps(treat~illact+crimjust+subprob, data=RED, estimand="ATT", verbose=FALSE, stop.method=c("es.mean", "ks.mean"), n.trees=3000)
JKP, I'm a little confused about the code you provided. Do I need to enter this into SPSS syntax only?